Model comparison
GLM-4.5-Air vs GPT-5.5 Instant
GPT-5.5 Instant is the stronger model overall, scoring 42.7 to 38.9 on the Noometry Index.
Last verified . 17 shared benchmarks.
Summary
- They share 17 benchmarks with published results for both. GLM-4.5-Air scores higher in 1 category and GPT-5.5 Instant in 7 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where GPT-5.5 Instant leads 48.9 to 35.0.
- GLM-4.5-Air has downloadable open weights; the other is API-only.
Side by side
| GLM-4.5-Air | GPT-5.5 Instant | |
|---|---|---|
| Provider | Z.ai (Zhipu) | OpenAI |
| Noometry Index | 38.9 | 42.7 |
| Released | 2025-07-20 | 2026-05-05 |
| Weights | Open | Proprietary |
| Context window | 131K | — |
| Max output | 98K | — |
| Input $ / M tokens | $0.20 | — |
| Output $ / M tokens | $1.10 | — |
| Results tracked | 27 | 27 |
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Category by category
Coding GPT-5.5 Instant leads
GLM-4.5-Air: 33.3 (#259), GPT-5.5 Instant: 44.3 (#74)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Coding | 1397 | 1433 |
| SciCode | — | 48.6% |
| GSO | 2.9% | — |
Reasoning Too close to call
GLM-4.5-Air: 24.1 (#166), GPT-5.5 Instant: 24.9 (#155)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Hard Prompts | 1379 | 1426 |
| Kagi LLM Benchmark | 43% | — |
| CritPt | — | 0% |
| Chess Puzzles | — | 12% |
| Epoch Capabilities Index | — | 142.52 |
| ForecastBench | 59.2 | — |
Math GLM-4.5-Air leads
GLM-4.5-Air: 36.2 (#170), GPT-5.5 Instant: 26.5 (#259)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Math | 1396 | 1420 |
| FrontierMath (Tiers 1-3) | — | 26.3% |
| FrontierMath Tier 4 | — | 2.4% |
| OTIS Mock AIME 2024-2025 | — | 68.1% |
| Omni-MATH | 39.1% | — |
Knowledge GPT-5.5 Instant leads
GLM-4.5-Air: 35.0 (#191), GPT-5.5 Instant: 48.9 (#74)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Expert | 1370 | 1409 |
| GPQA Diamond | — | 82.5% |
| Humanity's Last Exam | 8.1% | — |
| MMLU-Pro | 76.2% | — |
| Vectara Hallucination Rate | 9.3% | — |
| GPQA (HELM) | 59.4% | — |
Multimodal Not comparable
GLM-4.5-Air: —, GPT-5.5 Instant: 40.0 (#52)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Vision | — | 1250 |
| LMArena Document | — | 1403 |
Multilingual GPT-5.5 Instant leads
GLM-4.5-Air: 49.1 (#135), GPT-5.5 Instant: 52.8 (#80)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Non-English | 1366 | 1417 |
| LMArena Chinese | 1426 | 1456 |
| LMArena French | 1399 | 1428 |
| LMArena German | 1377 | 1411 |
| LMArena Japanese | 1348 | 1408 |
| LMArena Korean | 1308 | 1392 |
| LMArena Russian | 1373 | 1431 |
| LMArena Spanish | 1386 | 1429 |
Instruction Following GPT-5.5 Instant leads
GLM-4.5-Air: 69.6 (#171), GPT-5.5 Instant: 74.2 (#100)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1354 | 1406 |
| IFEval | 81.2% | — |
Long Context GPT-5.5 Instant leads
GLM-4.5-Air: 41.6 (#135), GPT-5.5 Instant: 43.4 (#96)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Longer Query | 1366 | 1422 |
Writing & Preference GPT-5.5 Instant leads
GLM-4.5-Air: 55.9 (#139), GPT-5.5 Instant: 61.8 (#85)
| Benchmark | GLM-4.5-Air | GPT-5.5 Instant |
|---|---|---|
| LMArena Text | 1384 | 1419 |
| LMArena Creative Writing | 1343 | 1419 |
| LMArena Multi-Turn | 1371 | 1433 |
| WildBench | 78.9% | — |
Frequently asked questions
Is GLM-4.5-Air better than GPT-5.5 Instant?
GPT-5.5 Instant is the stronger model overall, scoring 42.7 to 38.9 on the Noometry Index.
Is GLM-4.5-Air or GPT-5.5 Instant better for coding?
GPT-5.5 Instant scores higher on coding benchmarks: 44.3 versus 33.3 in the Noometry coding category.
How many benchmarks do GLM-4.5-Air and GPT-5.5 Instant share?
17 benchmarks have published results for both models. GLM-4.5-Air has 27 scored results on Noometry and GPT-5.5 Instant has 27.